Production of drying oils



July 26, 1949 H. s. BLOCH 2,476,955

PRODUCTION OF DRYING OILS Filed lay 31, 1946 2 Sheets-Sheet 1 n hw.

July 26 1949-- H. s. BLocH 2,476,955

A`PRODUC'HON QF DRYING oIns v Filed lay 31. 1946 I zsheets-sneet 2 INVEN TOR. fe/Illa 5 .Bloc/Ir Patented July 26, 1949 PRODUCTION OF DRYING OILS Hennan S. Bloch, Chicago, lll., assigner to Universall Oil Products Company, corporation of Delaware Chicago, lll., a

Application May 31, 1946, Serial No. 673,483

18 Claims. 1

The present invention relates to the production of high molecular weight polyolenic hydrocarbons which are particularly suitable for use as drying oils and as intermediates for the production of resins and otherl products requiring highly l unsaturated non-aromatic hydrocarbons as starting material. The invention concerns more specifically the production of said drying oils from oleiinic hydrocarbon charging stocks by reacting the same with substantially anhydrous hydrogen fluoride and further, it relates-to a process therefor which involves a particular ow of reagents and charging stock and a speciiic means of effecting the separation of the drying oil from an intermediate product formed during the process.

It is one object of the present invention to provide a process for the production of a hydrocarbon drying oil having a maximum degree of conjugated and non-conjugated unsaturation by maintaining reaction and recovery conditions such that polymerization of said drying oil hydrocarbons is maintained at a minimum.

It is another object of the invention herein disclosed to provide a particularly advantageous process flow and plant design for the commercial production of a hydrocarbon drying oil.

Still another object of the invention is to recover a valuable by-product hydrocarbon material from the present process which is utilizable as a high octane motor fuel.

A further object of the invention is to provide a process for the production of a hydrocarbon drying oil wherein a maximum recovery of reagents and catalysts utilized in the process of the invention is effected, and the recovery thereof in a condition suitable for recycling in the process. One embodiment of the present invention comprises contacting an olefinic hydrocarbon containing at least 4 carbon atoms per molecule with substantially anhydrous hydrogen fluoride, separating from the products thereof, a sludge phase containing a predominant proportion of the hydrogen uoride originally charged in chemical combination with a hydrocarbon as a complex addition compound thereof, decomposing said sludge in the presence of a metallic catalyst, hereinafter more fully described, separating a hydrogen fluoride phase and a hydrocarbon phase from the resultant product, and contacting said hydrocarbon phase with an alkaline reagent to remove therefrom residual dissolved hydrogen fluoride.

In one specific embodiment of the process comprising the present invention, a drying oil hydrocarbon is prepared by the following successive series of steps: A polymer gasoline formed by mixed polymerization of propylene and butylene, the product of which is fractionated to separate a portion boiling from about 30 to about 250 C., is intimately contacted with substantially anhydrous hydrogen fluoride in an amount ranging from about 0.1 to about 10 weight proportions of hydrogen fluoride to gasoline for a period of time within the range of from about 3 to about minutes to form a product which upon settling separates into an upper hydrocarbon phase containing predominantly saturated hydrocarbons suitable for use as a high octane number motor fuel (herein referred to as the upper hydrocarbon layer) and a lower layer sludge phase containing a predominant proportion of the hydrogen uoride charged to the reaction combined in the form of hydrocarbon-hydrogen nuoride complex addition compounds. The latter complex or sludge phase is separated and intimately contacted with liquid pentane to extract from said sludge the saturated hydrocarbons dissolved and/or entrained therein during the prior sludgeforming reaction, the lower immiscible sludge layer is then separated from said pentane and mixed with a hydrocarbon naphtha. fraction boiling from about to about 140 C., and the resultant mixture passed over a sludge decomposition catalyst comprising metallic copper at a decomposition temperature and pressure to release hydrogen fluoride therefrom and form thereby a bottoms product comprising said drying oil hydrocarbon dissolved in said naphtha. The naphtha. solution of the drying oil hydrocarbon is washed with a dilute aqueous solution of caustic followed by a further washing thereof with Water, the naphtha. hydrocarbons fractionated therefrom and a bottoms product separated from the fractionation which comprises said drying oil hydrocarbons.

Other specific embodiments of the present invention refer to alternative methods of conducting the individual steps of the process comprising said invention which include, among others, the following important modications of the principal process, which although inthe alternative, are distinct improvements in said process resulting in an increased yield of drying oil having a superior quality and a maximum recovery of reagents and catalyst employed in said process: (l) An improved method of contacting the hydrocarbon charging stock and hydrogen fluoride in the original sludge-forming reaction comprising countercurrent ow of said charge stock and hydrogen iiuoride to increase thereby the yield of sludge decomposition stage .having certain desirable ternative modifications arrasar vdrying hydrocarbons. normally present Ain said sludge which, if not removed from the sludge by a prior treatment such as the present extraction stage, appear in the iinal drying oil product. The above non-drying hydrocarbons, usually saturated in character, dissolved and/or entrained in the sludge are desirably removed from the same prior to the sludge decomposition stage for the reason that when the non-drying hydrocarbons are allowed to remain in the sludge, the drying oil hydrocarbons recovered in the sludge decomposition stage of the process possess an inferior drying eicicncy and generally result -in the formation of tach or incompletely dried films when said drying oil is utilized as a paint or varnish ingredient. (3) The utilization of a petroleum naphtha` fraction to dilute the drying oil hydrocarbons released in the sludge decomposition stage and thereby reduce or entirely eliminate the inter-polymerization of the drying oil hydrocarbons during the' decomposition of said sludge. The dilution effect of said naphtha is essentially a mass action effect whereby the unsaturated drying oil hydrocarbons are dispersed in said naphtha to reduce the possibility of inter-polymerization, which is allowed to proceed unchecked. greatly increases the molecular weight of the individual drying oil hydrocarbons and converts the latter into hydrocarbons containing fewer unsaturated double bonds, the resultant hydrocarbons being less satisfactory as drying oils. (4) An improvement in the catalytic of the present process which comprises utilizing an inert gaseous; carrier, introduced into the bottom of the sludge decomposition reactor to flow upward therein countercurrent to the downward ilow of sludge, thereby to strip the hydrogen iiuoride released by the catalytic sludge decomposition out of the reactor and from contact with the drying oil hydrocarbons ultaneously released when the sludge contacts the decomposition catalyst.I (5) An improved apparatus for contacting the inert liquid hydrocarbon extractant (preferably pentane'as 'indicated above) with the sludge to remove therefrom the non-drying oils as hereinabove indicated, such apparatus comprising a settling vessel containing an acid leg attached thereto as shown diagrammatically in Flgure3 and hereafter more fully described. Said acid leg provides for countercurrent extraction of the sludge with the hydrocarbon extractant in a simplified condensed form of apparatus. (6)' The vacuum distillation of; the drying oil product to separate speciiic fractions properties for the preparation of derivative products therefrom. It ls to be emphasized that the above recitation of displete, but others will be referred to in the following specications.

The procedure specied herein for the production Yof the present drying oil product as briey outlined in the above embodiments and the althereof as set forth in the above specific embodiments. will be amplified by describing a typical Operation in connection with the attached now diagramin Figure 1 which shows diagrammatlcally by the use of convenshown highly branched chain tional gures, generally in elevation, an arrange-` ment of the speciilc units of apparatus and the iiow of reagents and charge involved in the present process wherein the objects set forth above may be accomplished. The units of apparatus in the drawing are not to any exact or relative scale and are not intended to limit the scope of the invention in strict'k accordance thereto or otherwise.

Referring to Figure 1. a suitable oleilnic hydrocarbon charging stock is admitted under sufficient pressure to maintain the same in liquid phase at drogen fluoride reagent subsequently utilized in the process to catalyze the formation of the drying oil product. v

Before proceeding further with the description the process and apparatus for drying the charging stock and the subsequent steps of the process, it is advisable tov define in more concrete terms the nature of the hydrocarbon charging stock utilizable in the present process. The types yield desirable sludges and ultimately the desired drying oil product, in general, are the alip tic and cyclic non-aromatic hydrocarbons, that is, the straight and branched chain or cyclic olenic and branched-chain parafiinic hydrocarbons. Of the above general classes ofl hydrocarbons utilizable herein, the paraiiins containing at least 4 carbon atoms per molecule and the straight or branched chain monoor polyolefins or acetylenes, as weil as cyclic olens Vare the preferred starting materials, since these hydrocarbons form sludges which when treated in accordance with the present process yield a drying oil product composed chiey of hydrocarbons having the desired molecular-.weight (preferably from about 250 to about 600); said hydrocarbon product also contains highly unsaturated components containing olenlc double bonds in a preferred conjugated relation to one another. The charging stock, moreover, may comprise simply a single hydrocarbon component -of suitable structure, but if a Imixture of hydrocarbons such as a suitable petroleum fraction. is more available, the'process may be operated utilizing said mixture as` charging-stock. The components, further, may be of diverse structure, but no substantial proportion of said mixture should be of aromatic character. I have found that it is desirable to maintain as low an aromatic content in the feed as possible, because the yield of desirable drying oil is lowered indirect proportion to the aromatic content of the feed stock. Typical of the hydrocarbon mixtures which I have found to be especially suitable in the formation of a hydrogen uoride sludge are certain fractions of crackedor polymer gasoline (preferably the latter) having'a boiling` range of from about 30 to about 250 C. If a cracked gasoline is selected as the charging stock it is desirably A tributed/on trays or merely packed as rigid particles in said dryer 6. The hydrocarbon charge flows through the granules of dessicant, emerges from the top of dryer l, through line 1, containing valve 8 and flows therefrom into the sludgeforming reactor indicated on the diagram as contactor 9, hereinafter described. The dessicant distributed in dryer 6 gradually becomes inactive by continued adsorption of increasing quantities of moisture from the charge so that the dessicant must either be replaced or regenerated to accomplish further drying.

To provide for continuous flow of hydrocarbon charge into the process, an auxiliary drying vessel is maintained -in parallel ,relationship to dryer 6 by connecting line 4 to line I0, closing valve 5 and diverting the charge into line I0, through valve II, into dryer I2 containing fresh dessicant. The hydrocarbon charge ows through the dryer as described for dryer 6 and emerges therefrom through line I8 containing valve I9 into line 'I which leads to the sludge forming contactor 9. Although two vessels are indicated as dryers, the drying system may comprise any number of vessels in series or parallel in order to accomplish the desired degree of dry- While the charge is thus diverted through auxiliary dryer I2 the dessicant in dryer 6 may be regenerated, said regeneration usually being accomplished by passage of a heated inert gaseous material over the dessicant until the Water content thereof is lowered to a point at which the dessicant will again dry the hydrocarbon charge effectively. For the purpose of regeneration, the inert gas which may be nitrogen, carbon dioxide or a low molecular Weight parailinic lhydrocarbon,`such as propane or butane, is introduced into line I3 at a temperature of from about 150 to about 200 C., .through valve Il into the bottom of dryer 6 and flows upwardly therethrough, issuing from the top of dryer 6 through line I5, valve I6 and line I1 to be recycled or discharged from the process. When the dessicant in drying vessel I2reaches the poirit at which it becomes ineffective for further drying of the charge, the flow of hydrocarbons is again diverted into regenerated drying vessel 6 by closing valve II and opening valve 5. The regeneration of the dessicant in vessel I2 is then accomplished by closing valve I4 and forcing the heated inert gas through line 20 and valve 2| into the bottom of vessel I2. The inert gas, laden with moisture from the dessicant, flows from'the top of vessel I2 .through line 22, valve 23 and line I1 to be discharged from the process or recycled therein.

The dried hydrocarbon charge flowing from drying vessel 6 through line 'I enters sludgeforming contactor 9 through the bottom of the apparatus provided therefor and therein contacts substantially anhydrous hydrogen fluoride for the production of the hydrogen fluoride sludge from which the present drying oil is derived. In preparing the hydrogen fluoride sludge for the process of this invention, the hydrocarbon charging stock is contacted for a period of time, not exceeding about 2 hours, with approximately anhydrous hydrogen fluoride which may contain a maximum of about of water but is preferably of from about 95 to about 99|% concentration, at a temperature within the range of from about 20 to about 200 C. (preferably from about 30 to about 125 C.) and at a superatmospheric pressure sufficient to maintain the reactants in liquid phase during the reaction. The hydrogen iluoride 6 is introduced. from storage into line 24 through valve 25, line 26, and valve 21 into the top of the hydrogen fluoride sludge contactor, and being heavier than the hydrocarbon phase, it tends to gravitate toward the bottom of the contactor where it meets fresh incoming hydrocarbon charging stock entering through line 1. The

Weight ratio of hydrogen fluoride to hydrocarbons maintained in contactor 9 may range from about .05 to about l0 proportions of hydrogen fluoride to hydrocarbons, preferably at about a 1:1 to about a 0.5:1 ratio.

Although the hydrogen fluoride sludge contactor,`vesse1 9 on the diagram, is indicated as a tube reactor, any suitable apparatus or reactor may be utilized to -contact .the hydrocarbon reactant with the liquid hydrogen fluoride catalyst in contactor 9. It is desirable that very intimate contact between the liquid hydrocarbon charge and hydrogen fluoride be maintained for a period of .time suflcient for the reaction to proceed to substantial completion (usually after a period of about one-fourth hour to about two hours). In general, some form of agitation, such as mixing, stirring, etc., is used, Which forms an intimate mixture or emulsion of hydrocarbon and hydrogen fluoride. One particular form of apparatus which I have found to be especially desirable is indicated in Figure 2 of .the attached diagram. hereinafter described. The arrangement of the vessels indicated in Figure 2 is intended to obtain maximum sludge production from a given charge of hydrogen fluoride and hydrocarbons at a maximum efficiency in the formation of the sludge.

-The dried hydrocarbon charge indicated as issuing through line 'I from the drying vessel in Figure 1 enters line 1in Figure 2, passes through valve 20| and is charged into the bottom of vessel 202 where it contacts partially used hydrogen fluoride, the source of which is hereinafter referred to and which enters vessel 202 through line The hydrocarbons and used hydrogen fluoride are intimately mixed or emulsiiled as they flow upwardly through vessel 202 by stirrer 204 maintained rapidly revolving by motor 205. The hydrogen fluoride sludge emulsion issued from the top of vessel 202 and enters sludge settler 205 by way of line 206. In vessel 205, thev sludge emulsion formed in contactor 202 is allowed to settle and stratify into a heavier sludge layer and an upper `hydrocarbon layer. The sludge is removed from settler v205 through line 40 and valve 4I ,into an apparatus subsequently described for further processing of the sludge. The upper hydrocarbon layer separating in settler 205 is removed through line 201 and valve 200 and charged into the bottom of a second sludge-forming contactor indicated in Figurev 2 as vessel 209. 'Ihe upper layer hydrocarbons separated in settler 205 ordinarily contain a quantity of less reactive hydrocarbons which donot form a hydrogen fluoride sludgeas readily as the more reactivehydrocarbon components of .the chargingstock. .The hydrocarbons introduced into vessel 209 are contacted with the more reactive fresh hydrogen fluoride introduced through line 26 and valve 21 into the bottomof vessel 209. As indicated for vessel 202 a stirrer is also maintained in vessel 209 to eilect intimate contact of the hydrogen iluoride with the hydrocarbon charge. Stirrer 2I0 directly attached by shaft to motor 2II is thus provided for accomplishing the desired mixing of the hydrocarbons and hydrogen fluoride. The efuent from vessel 209 is conveyed by line 2|2 into settler 2I3 where said eiliuent separates ,7 into a bottom layer-'containing substantiallyall of the hydrogen fluoridecharged and comprises the partially used hydrogen fluoride hereinbefore referred to which is withdrawn from vessel 2|3 through line 203 and valve. 2i4 and is directed into vessel 202 as previously noted for contacting the fresh hydrocarbon charge. The upper 'hydrocarbon layer separating in settler 2|3 is removed through line 3| containing valve 32 and treated as subsequently indicated herein to recover therefrom a valuable by-product high octane moto fuel.

Returning to Figure 1 for-.the descriptionof the present process, the products formed in hydrogen fluoride sludge contactor 9 are transferred through line 29, and valve 29 into sludge settler 36 where a two layer system separates on breaking of the emulsion of hydrogen iiuoride sludge and "upper layer hydrocarbons formed in vessel 9. 'I'he desired sludge layer separating in settler 3l contains a predominant proportion of the hydrogen fluoride originally charged to the system in the form of a hydrocarbon-hydrogen fluoride complex from which the present drying oil ;is derived after removal of the hydrogen fluoride from said complex. The sludge separating as the lower layer in vessel 30 is removed through line -46 containing valve 4| and as it flowsV therethrough it is mixed with the inert saturated liquid hydrocarbon heretofore mentioned for extracting the dissolved and/or entrained non-dryingV hydrocarbons from the sludge. 'I'he hydrocarbon extractant, indicated on Figure 1 as pentane which comprises a preferred material for such purposes (although other inert low boiling hydrocarbons such as butane or propane may be used) is introduced through line 42 under pressure supplied by pump 43 into line 44 containing valve 45. Line 44 connects with line 40 and at the point of juncture the sludge and extractant mix prior to introducing the mixture into mixer 46. In preparing a synthetic drying oil from a hydrogen fluoride-hydrocarbon complex, I have found that the drying oil recovered from said complex often drys to a lm which is permanently sticky and tacky rather, than to one which is hard and rm to the touch as is required in coating compositions unless the sludge, prior to separation of the drying oil therefrom, is treated with the inert hydrocarbon extractant to remove certain undesirable hydrocarbons entrained or dissolved in the sludge. If the Ihydrogen iiuoride sludge complex is treated or extracted in the manner indicated, .the resulting drying oil product has greatly improved drying properties and sets to a rm hard iilm because the pentane extractant has removed certain saturated hydrocarbons which boil too high to evaporate but yet are not separable from the drying oil hydrocarbons by subsequent fractionation and which if allowed to remain in the resultant product do not dry as the unsaturated drying oil hydrocarbons do, but act as tacklfying agents in the drying oil composition.

The pentane introduced through line 44, into line 4l carrying the sludge from settler 361s intimately mixed with the sludge by passage through mixer 46 which may containa series of bailles or orifices where the pentane` is tortuously mixed with the sludge to form an emulsion. The latter emulsion is withdrawn through line 41 and valve 4l and introduced into pentane settler 49 where the emulsion is-allowed to separate into two dis-` tinct layers, an upper pentane layer containing a small percentage (generally not exceeding about] 1%) o! hydrogen fluoride and a lower extracted sludge layer. The upper pentane layer is .transferred by means of pump.I 62 from settler 49 through line 56 containing valve 5| into line 63 containing valve 54, said line 53 connecting with line 55'which in turn transfers the pentane containing dissolved hydrogen fluoride into liney 3| hereinafter referred to.

The upper hydrocarbon layer separating in sludge settler 30- has dissolved therein a small amount of hydrogen fluoride in the order of about 1% by weight of said upper layer. Since the dissolved hydrogen iiuoride is a relatively valuable catalyst in the present process, which .may be separated from the hydrocarbon layer and returned into the process flow, it is desirably removed -therefrom before the latter is discharged from the process. Saidupper layer is withdrawn from sludge settler 30 through line 3l containing valve 32 and is introduced by means of pump 33 through line 34 containing valve 35, heat eX- changer 36 and line 31 containing valve -38 to hydrogen fluoride stripperv 39 which is usually a fracticnating column either contact materials, such as stainless steel jack chain or contains bubble decks of the ordinary design. Heat exchanger 36 may be employed as a heating or cooling means depending upon the temperature of the upper layer hydrocarbons and pentane charged into the hydrogen uoride stripper 39. It is generally preferred thatv the temperature of the hydrocarbon-hydrogen fluoride mixture introduced into stripper 39 be at least about 50 C. to provide for suiiicient volatility of the hydrogen fluoride and enable the latter t0 ash overhead when the charge is admitted into said stripper 39.-

In stripper 39 the hydrogen fluoride dissolved in the upper hydrocarbonlayer formed in contactor 9 and the pentane-hydrogen uoride solution separatedin pentane settler 49 are flashed over-head from stripper 39 through linev 56 'containing valve 51 and passed into condenser 58 where the light hydrocarbon,vapors and hydrogen fluoride are condensed into a liquid' fraction which enters receiver 60 through rundown line 59. The hydrogen fluoride removed over-head in column 39 is present in receiver y6l) in substantial excess of its solubility in the pentane present and therefore two layers are formed'in receiver 60. 'I'he lower hydrogen fluoride layer is withdrawn through return line 6| containing valve 62 and is supplied by means of pump 63 through line 64 containing valve 65 to line 66 containing valve 61 thereby conveying the return hydrogen uoride either into line 24 and HF make-up or storage orr into line 26 for recycle into contacter 9. 'I'he upper hydrocarbon layer consisting chiefly of pentane in receiver 60 63 containing valve 69 and recycle pump 10 which returns the pentane through line 1I- containing valve 12 into pentane'supply line 42 and connects therewith for recycling the pentane to the sludge extraction stage. A substantial portion of the pentane, however, from line 66 through line and is forced by pump 15 via line 16 containing valve 11 into the upper portion of column 39 to provide the requisite hydrocarbon reiiux in the fractionation effected vin column 39.

The saturated hydrocarbons formed in the contacting stage of the present process which sepa- 13 containing valve 14 rate from the sludge as an upper hydrocarbonl layer in sludge settler .30 contain a number 'of packed with suitablek is withdrawn through line f is desirably withdrawn high octane fuel components. The latter hydrocarbons which boil at a temperature higher than the pentane or hydrogen uoride separated in column 39, therefore accumulate as a bottoms fraction in the latter column. The latter fraction is removed through line 18 containing valve 19 and is discharged from the process or transferred to a gasoline separation zone for the removal of desirable gasoline boiling range fractions therefrom, not indicated on Figure 1.

The present invention includes'as a preferred embodiment thereof, an improved method of the sludge is intimately mixed with an inert saturated hydrocarbon extractant such as pentane, and the latter extractant together with undesirable hydrocarbons dissolved and/or entrained in the sludge are subsequently allowed to separate from the sludge and withdrawn. The improvement herein referred to eliminates the multiplicity of apparatus associated with the process described in Figure 1, the apparatus comprising mixer 46 and pentane settler 49. Said improvement provides a highly efficient unit apparatus for accomplishing the purpose of the above combination of apparatus. The improved device is essentially a sludge settler containing an acid leg wherein pentane is introduced to extract the sludge in countercurrent flow with said sludge. Figure 3 illustrates the improved apparatus referred to in the present embodiment. For the purpose of this process, the hydrogen fiuoride sludge layer separating in settler 3D is removed therefrom through line 40 containing valve 4I and introduced into sludge extractor 300. The sludge immediately flows into acid leg 300A, an integral part of the extractor, finally filling the acid leg and eventually entering the horizontal tank-like portion of the apparatus. Liquid pentane is thereupon introduced into the acid leg through line 44 at a point therein somewhat above the extreme bottom of the leg, above the sludge outlet. The pentane, having a specific gravity less than the sludge, percolates upwardly through the column of sludge contained in the acid leg and as it does so, it extracts the undesired saturated hydrocarbons from the sludge. The pentane extractant fills the upper tank-like portion of the apparatus and under continuous operation, with the entire'system in equilibrium, theh pentane flows out of extractor 300 through line 50 containing valve 5I and pump 52 which forces the pentane layer into the hydrogen fiuoride stripper as heretofore described. When the `process is operated under continuous flow, as is normally the case in commercial operation, the extracted sludge is removed through line 8D containing valve 8| as rapidly as raw sludge is introduced into the extractor through line 4U. Pentane is also charged into extractor 300 at a rate consistent with the desired flow and at a rate suillcient to maintain at all times a two layer system in the tank-like portion of extractor 300.

According to the method herein described for the preparation of an improved drying oil hydrocarbon product from a hydrogen fluoride sludge, conditions are established and a process is operated in such a manner that the resulting drying oil product is composed of hydrocarbon components having a relatively large number of conjugated as well as non-conjugated double bonds per molecule which thereby give the drying oil product the ability to dry rapidly and completely to a hard tough film on exposure to air. The above objectives are obtained by carefully conconducting the sludge extraction stage wherein trolling the conditions under which the sludge is decomposed and by operating the decomposition stage of the process so that the polymerization of the drying oil hydrocarbons is maintained at a minimum. I have found that polymerization or condensation of the drying oil components during this decomposition step is a most significant factor in determining the number of conjugated and non-conjugated unsaturated bonds contained in said drying oil hydrocarbons and therefore, also, the dryingv efficiency ofV the product.

In the present method of this invention for `the sludge decomposition stage of the process, a catalyst is utilized which has the ability to release the unsaturated drying oil hydrocarbons from combination with the hydrogen fluoride in said sludge at a lower temperature and at a higher rate of speed than may be accomplished by strictly thermal decomposition in the absence of saidcatalyst. The method eects the immediate separation of the drying oil hydrocarbons and hydrogen uoride following the liberation of these components from the sludge, thus substantially-eliminating the contact period between the drying oil hydrocarbons and the free hydrogen fluoride in the reactor and obviating a major factor causing polymerization of the drying oil product. I believe the catalyst serves a further purpose in that its surface also inhibits polymerization and condensation of the hydrocarbons released in the decomposition.

According to the present process, the hydrogen fiuoride sludge is charged at a suitable temperature into a packed flashing column containing as a packingl material a catalytic agent of the class hereinafter specified. In one typical method of operation, the sludge Just prior to being charged into the catalytic decomposition tower is preheated to a temperature of from about 50 to about 200 C., depending upon whether atmospheric pressure or a pressure above or below atmospheric is employed in the decomposition tower. I have found` that a particularly desirable arrangement for conducting the present process is that of heating the sludge to a temperature of from about 125 to about 200 C. under a slightly superatlnospheric pressure immediately before it enters the decomposition tower while maintaining said tower at about atmospheric pressure or lower. The hydrogen fluoride released by contact of the sludge with the decomposition catalyst inthe catalytic flashing tower may then be compressed and condensed with relative ease. Alternatively, the catalytic decomposition may be carried out at a pressure sufficiently above admospheric so that the liberated hydrogen fiuoride may be condensed with ordinary cooling water without further compression.

During the catalytic decomposition of the sludge or just prior to its introductioninto the catalytic decomposition column, it may be mixed with a non-reactive diluent, usually a saturated hydrocarbon such as a paramn,.whichboils within such a range that a substantial portion of it remains liquid during the sludge decomposition stage but at a temperature suiciently beabout 120 to about 150 C. although this boiling range maybe varied according to other operating conditions. The hydrocarbon diluent 4has thesition column as the more volatile hydrogen fluoride passes upwardly through the column and escapes into the vapor line. The' diluent thus effectively removes the drying oil hydrocarbons from the sphere of active polymerization cat-alyzed by hydrogen fluoride, a normally active polymerizationv catalyst. The inert hydrocarbon diluent appearing as a bottoms fraction with the desired drying oil product in the decomposition column is subsequently removed from the mixture and may be recycled to the catalytic decomposition column. One type of diluent which I particularly prefer because of its inertness to hydrogen uoride and because it may be readily separated from the drying oil hydrocarbons in a subsequentA fractionation step is'the naphtha fraction of a straight-run petroleum' distillate and preferably a fraction boiling from about 130"A to about 150'C. The naphtha, in a pre-l ferred embodiment of the present invention, is mixed with the sludge just prior to theintroduction of the sludge into the catalytic decomposition column, although the naphtha may also be introduced in the column asa separate stream. Another preferred inert diluent comprises certain fractions boiling in the desired range of the saturated upper layer hydrocarbons separated in vessel 30. i

As operated by the above series of steps, the process results in the separation of a gaseous hydrogen fluoride eilluent removed from the top of the catalytic decomposition column containing from about 90 to over 99% hydrogen fluoride. depending upon the conditions maintained in the column, such as the rate of throughput, .etc.` As a bottoms product or residue in the column, a

l' hydrocarbon fraction comprising the desired drying oil product of the present process containing hydrocarbons having a high degree of conjugated and non-conjugated unsaturation in solution with the naphtha diluent is removed from the d ecomposition column.

The mixture of sludge and naphtha may be heated or cooled prior to its introduction into the flashing column containing the sludge de;- composition catalyst, or the naphtha or sludge may be separately heated or cooled 'in orderto/f55l control the heat input into the decomposition vessel, it being particularly advantageous at times to introduce' the preheated naphtha in Vaporous form. If vthe sludge is rbrought to the optimum temperature for decomposition prior to solid at the temperatures specified for the operation of the process and which are substantially inert to the continued action of free hydrogen uoride In addition to these properties, the catalytic packing material should ypossess the following physical and mechanical properties: (l)

It should be capable of accelerating the decompospeaking, the requirement that-the catalyst be inert to the continued action of hydrogen iluoride eliminates such materials as silica-containing substances -anci metals which' are readily attacked by free anhydrous hydrogen fluoride, especially those metals'high vin the electromotive series of elements. Ifhave found that certain ymetals and special forms of non-activated carbon are especially desirable catalysts for the decomposition reaction. Of the metals 'I prefer to utilize copper, aluminum, cobalt, lead, cadmium and certain alloys of copper such as brass. The

its contact with thevcatalyst thejcolumn does not under these conditions require external heating and may be operated as an adiabatic reactor. It may be heated however, if, for example, the rate of through-'put caused an undesirably large temperature drop in the column. According to another method of operation, the mixture of sludge and naphtha is introduced cold or at ambient temperatures into a heated ashjdecomposition column maintained by external heating at the optimum temperature to effect the decomposition of the sludge.

The catalysts utilizable in the present process for decomposition of hydrogen fluoride sludges broadly comprise those substances which are products recovered from the decomposition of the hydrogen fluoride sludge in the presence of metallic -copper as catalyst is generally in a highly desirable condition; the percentage recovery and concentration of hydrogen fluoride is -high so that the hydrogen `fluoride may be recycled in the process without extensive removal oi'l water therefrom; and the recovery of drying oil hydrocarbons approaches a maximum and the hydrocarbons thus recovered retain alarge percentage of their original conjugated and nonconjugated unsaturation which characterize the drying oil hydrocarbons immediately upon release of the, hydrocarbons from the sludge.

Referring again to Figure 1` which indicates the preferred ow in the present process, the pentane extracted sludge separating as a lower layerxin pentane settler 49 is-removed by means of pump 82 through line 80 containing valve '8|' and mixedwith the inert hydrocarbon diluent referred to above (preferably a naphtha fraction boiling from about 130 to about 150 C.) as it flows through line 80, saiddiluent entering line by connection with line 84 which feeds the. diluent into the system. TheA diluent, hereindryer and ows through said dryer contactingv therein the dessicant to the top thereof into line 8l containing valve 89 and into line 80 where it 4mixes with the sludge as previously noted. Although the' process lsyin general operable when utilizing any proportion of naphtha to sludge, it is preferred to maintain the proportion at from about 0.5:1 to about 10:1 volumes of naphtha per volume of sludge.

exchanger v wherein the mixture is heated to a temperature of from about 50 to about 200 C., preferably up to about'150" C. The mixture, after being heated to the desired temperature, exits heat exchanger 90 by wayof line 9i through y The mixture of sludge and naphtha is forced by means of pump82 into heat 13 valve 92 into catalytic sludge decomposition column 93 wherein the sludge is-decomposed in the presence of a catalyst of the ty'pe hereinabove specified.v to release a vaporous fraction containing hydrogen iiuoride and a'liquid fraction comprising the drying oil product dissolved in the naphtha diluent. The mixture charged into the sludge decomposition column is introduced at a point in the upper portion of said column so that the hydrogen iluoride, which is -immediately released upon coming in contact with the sludge decomposition catalyst, is rapidly carried out of the column through vapor line 94 containing valve 95 into condenser 9 6 wherein the gaseous hydrogen iiixoride is cooled to a liquid fraction which is removed from condenser 96 through line 91, valve 99, into the receiver 99.

According to one of the preferred alternative means of operating theimproved sludge decomposition process hereinabove briey outlined in a specific embodiment of the present invention, an inert gaseous carrier is introduced into the bottom of the sludge decomposition reactor to strip the hydrogen uoride vapors released by the sludge decomposition reaction from contact with the drying oil hydrocarbons likewise released by the decomposition of the sludge. The inert gaseous carrier herein referred to is a substance which remains gaseous under the temperature and pressure conditions at which the decomposition reactor is operated and which does not react in any manner with the sludge, hydrogen uoride, or drying oil hydrocarbons present in the reactor during the decomposition process. Generally speaking, such gases include oxygen-free nitrogen, an oxide of carbon, preferably carbon monoxide, and low molecular weight parailinic hydrocarbons such as methane, ethane, propane; the butanes, etc. which have been thoroughly dried prior to their introduction into the decomposition reactor. Moreover, the inert carrier may be a substance which is liquid under normal conditions but which may be vaporized by heating; the resultant vapor is then utilized in its vapor state as the gaseous carrier herein specified. The normally liquid substance is usually a parafiinic hydrocarbon, but whatever its composition, it must be substantially insoluble in liquid hydrogen iluoride, so that it may be subsequently separated therefrom and recycled in the process. The preferred gaseous carriers are the low molecular weight parafilns and of these I prefer to utilize those below pentane in "molecular weight. The gaseous carrier is desirably heated to approximately the sludge decomposition temperature,

charging the sludge, the temperature o! the decomposition reactor, the size of the particles of sludge decomposition catalyst and other factors aii'ecting the reaction. These factors may be determined for the particular operation by experimental procedure and no attempt shall be made here to define specifically the limits thereof because of their mutual relationship with the conditions affecting the decomposition reaction.

The catalytic sludge decomposition reactor is ordinarily a tube reactor containing a xed bed of relatively'loosely packed catalyst particles with void spaces between said particles to allow for the passage of the liquid sludge and vapors through the catalyst bed. When an attempt is made to introduce heat into the reaction zone to effect the endothermic sludge decomposition reaction by heating the outside walls of the decomposition reactor it is found that the reactants, within the reactor adjacent to the outside wall where heat is applied, are increased in temperature to a point considerably higher than the average temperature desired for' the reaction, while the reactants at the center of the decomposition reactor which receive heat only by conduction through the catalyst bed do not receive sufilcient heat for the optimum .sludge decomposition.

and preferably to a temperaturev somewhat higher, Within the range of from about 150 to about 300 C., depending upon the temperature selected for operation of the decomposition reactor. The rate at which the gas is introduced into the reactor is carefully controlled so that the heat input necessary to accomplish the decomposition of the hydrogen uoride sludge is maintained within the range desired, While at the same time maintaining the rate of input suiliciently low to prevent entrainment and carryover of sludge and/or hydrocarbons into the hydrogen fluoride vapor stream. The rate of input which I have found to be especially suitable for the present process'is within the range of from about 0.1 to about 10 Volumes of gas per volume of reactor space per minute, but at a rate such that the total vapor Velocity in the reactor does not exceed about 0.5 it. per second, although this rate is also dependent upon the rate of Thus, an undesirable temperature gradient exists within the catalytic reactor resulting in the temperature of the reactants adjacent to the source of heat being too high, causing deterioration of the drying oil hydrocarbons, while the temperature of the sludge at the center of the column is below the value at which optimum sludge de composition takes place. Furthermore, in the alternative means of introducing the heat of decomposition into the reactor by heating the sludge, it is found that in order to heat the sludge to the temperature required `for complete decomposition, considerable polymerization of the product results thereby.

' I have found that a large proportion oi the heat required for the sludge decomposition reaction may be introduced into the reactor by heating the inert carrier gas to the above preferred temperature and by means of this modication it is not necessary to heat the sludge to a temperature in which the drying oil product begins to rapidly deteriorate. Since the inert gaseous carrier is introduced into the bottom of the decomposition reactor, the gas flows upwardly through the bed of catalyst, countercurrent to the downward flow of sludge and thus, not only carries heat into the center of the decomposition column, but also carries out the hydrogen uoride vapor from the decomposition reactor,` thereby preventing furthere contact with the drying oil product. The overall recovery of hydrogen fluoride is also increased because the hydrocarbon product collecting as a bottoms fraction in the reactor is free of substantially all of the hydrogen fluoride which is normally dissolved in the product and which ordinarily (in the absence of the present embodiment of utilizing the carrier gas) would be subsequently washed to remove therefrom said dissolved hydrogen iluoride.

Referring to Figure 1 which diagrammatically presents the flow of the present process, the inert carrier gas is introduced into the system from a reservoir of the gas, not shown on the diagram, through line lill at a temperature of from about 150 to about 300 C., through valve |02' and is increased in pressure by compressor |03' to force the W of the gas through the catalyst bed in the decomposition reactor.' The carrier gas, at its `15 desired pressure, leaves said compressor through line |04* andy enters sludge decompositionlcolumn 93 through thebottom of reactor, flowing upwardly through the catalyst distributed in reis condensed. The inert gaseous carrier and liquid hydrogen fluoride -ilow out of condenser 96 through line 91 containing valve 99 and enters receiver 99 wherein the liquid hydrogenl uoride accumulates as a liquid condensate while; the

gaseous carrier separating from the hydrogen fluoride therein is pumped through line |05' containing pump |00' and 'is recycled to the bottom of reactor 93 through line |01' containing valve |03 into line |04'. When the inert gaseous jcarrier utilized in the process is a substance which is liquid at normal conditions andat the temperature Vat which the hydrogen uoride isliquiiled in condenser 90, both liquidseseparate in settler 99 as two distinct layers, a lower hydrogen fluoride layerv and an upper liquid layer. In connection with the use of an inert liquid it lis usually necessary to supply a heat exchanger in fline but not shown on the diagram, to vaporize the inert liquid before introducing thevsame into line |04' and recycling the inert vapor into reactor 93. I p

Referring again to the liquid hydrogen iluoride layer which separates in receiver 99, all or a portion of the same may be withdrawn from said receiver 99 and recycled to stripper 39 toprovide for suil'lcient hydrogen uoride reflux in the latter vessel. For this purpose, the liquid hydrogen fluoride is withdrawn through lin'e |00, valve |0|, pump |02, line |33, through valve |04 and discharged into line l5 which connects with line 9| supplying the charge to said hydrogen fluoride stripper 39. Under normal operation, however, it is generally preferred to recycle a major proportion of the hydrogen fluoride contained inl receiver 90 back to conta'ctcr 9 wherein the sludge of the present process is produced. To this/fend, the hydrogen fluoride is removed through line Ill, valve |00. Dump |01. and line |09 connecting with une ss which feeds the hydrogen fluoride through valve 61 into line 2l leading to the hydrogen fluoride reservoir or into line 26 through valve 21 into contactor 9`for recycling purposes. In order to control the water content of the 'hydrogen fluoride in the present process and maintain.. its concentration at its optimum value of approximately 95 to about 99% hydrogen fluoride, a portion of the hydrogen fluoride in line |08 from reservoir 99 is.` continuously removedy from the hydrogen uoride stream to separate water therefrom in the form of .a constant-boilremoved therefrom throughline |09, valve ||0 and heat exchanger Ill to hydrogen fluoride dehydration column ||2 which may be a fractionator or merely a ilash chamber in which the heated hydrogen fluoride is distilled to remove fractions o f the desired composition. In column ||2 any water that is present in the hydrogen fluoride is concentrated in the higher boiling reilux condensate, usually an azeotropic or constant boiling mixture (indicated on Figure 1` as C. B. M.) of water and hydrogenuoride withdrawn fromcolumn ||2 through line ||3 and valve IM. over-head from dehydrating column ||2 through 5l line H5 and valve ||3 and 'is passed into condenser I|1 where the hydrogen fluoride vapors are liquefied. The condensed liquid hydrogen fluoride is withdrawn from condenser I I1 through line ||9 containing valve `||9 and run intore- Ll0 ceiver |20. Usually av portion of the hydrogen fluoride condensatefis withdrawn from receiver |20 through line v|2| which connects with line |22 containing valve |23 and is forced bypump |24 into line |2l containing valve |20 to supplysui- .cient hydrogen iiuorldereilux into vciehydrating column ||2. hydrous hydrogen uoride condensate in receiver is recycled into the hydrogenv fluoride supply line by withdrawing the same through line |2|. 20 valve |21 and pumping the same byv means of pump |29, into line |23, through val've V|30 from line k|29 into line 90 vleading to hydrogen fluoride supply line 23 or into storage through valve 2l and line 20. A

25 As previously noted, the catalyzed sludge de.

composition reaction occuring in column 33 effectively decomposes the hydrogen fluoride-drying oil complex containedV in the sludge immediately upon the sludge coming in contact with the indicated decomposition catalysts. De'pend-y `ing upon the temperature and pressure at which column 93 is operated, the hydrogen fluoride .vapor fraction which flashes over-head through line 94 when the mixture of rsludge-and naphtha 35 contacts the catalyst, may contain from 90 toas high as 100% hydrogen uoride. Dyillg oil hydrocarbons released by the decomposition reaction, in solution with the naphtha diluent. are relatively higher boiling than the hydrogen nuoride and accumulate in the bottom of column 93 from which they may be withdrawnthrough i line 3| bymanipulation of valve |32. Because thedrying oil-naphtha hydrocarbon mixture usually dissolves a small quantity of free hy- 4'5 drogen fluoride (less than about 0.5% at atmos` Y pheric pressure), unavoidably retained by the lmixture in solution for combination therewith, the mixture is preferably contacted. with an alkaline reagent toneutralize the residual free hydrogen uoride dissolved therein and thus reducing the possibility of the drying. voil hydrocarbons polymerizing when vthe mixture is subsequently heated to .i'ractionate therefrom the naphtha diluent. It is well known that hydrogen fluoride is an active polymerization catalyst and it is therefore desirable to remove all traces of the free reagent from the present product. This is even more apparent when it i's realized that the highly unsaturated drying oil hydrocarbons tend to polymerlze at even mild conditions of temperature and pressure. which .is enhanced in the presence of minute quantities of the hydrogen fluoride polymerization catalyst.

AThe bottoms product from column 93, with- A drawn through line |3| and valve |32, is conveyed by means of punp-Vv |33 into line |34, through valve- |35 and is charged into the bottom of caustic scrubber |38 where the hydrocarbon mixture comprising said bottoms product is allowed to percolate upwardly through a stream of aqueous caustic flowing ldownwardly through the column from its point of lintroduction at the top thereof through line |31 containing valve |38. The caustic scrubbing solution may be of 7 5 any concentration, but preferablya solution hav- Dry hydrogen fluoride is withdrawn A maior proportion kof the -an' ing a low viscosity (such as ai solution containing up to about sodium hydroxide) is utilized in column |38. sColumn |38 may also contain a suitable packing material, such as quartz chips or particles of ceramic ware to increase the surface contact between the hydrocarbons and caustic solution and thus effect a more efllcient scrubbing action. Instead of utilizing an aqueous solution of caustic in scrubblng tower |38, it may be alternatively packed with a suitable solid alkaline reagent. Soda lime, being a particularly effective and inexpensive reagent, may be utilized as the solid alkaline reagent to effect neutralization and removal of any dissolved hydrogen fluoride in the hydrocarbon mixture. A particular advantage is also obtained in the use of -a solid alkaline reagent instead of the aqueous caustic solution in that the subsequent water scrubbing treatment and naphtha dryer 88, which removes water from the recycled naphtha fraction, may be thereby eliminated from the process flow. When employing the aqueous caustic solution, used or partially spent caustic solution gradually gravitates into the bottom portions of scrubber |38 and is drawn off through line |38 containing valve |40 to recycle line |38 if the solution contains any unused caustic dissolved therein. If relatively spent, the solution is merely discharged from the process. The hydrocarbon fraction which rises to the top of column |36 and accumulates in that portion, is withdrawn through line 4| containing valve |42 and by means of pump |43 the hydrocarbon mixture is forced through line |44 containing valve |45 into water scrubbing column |48 where again, the hydrocarbons, being lighter than the water, percolate upwardly through the column and accumulate at the top thereof. Fresh or recirculated water is introduced into the top of the column through line |41 containing valve |48 and after ilowing downwardly through the rising stream of hydrocarbons in column |48 is withdrawn through line |48 and valve |50.

The hydrocarbon mixture containing naphtha and the desired drying oil product accumulating in the top of scrubber |48, being free of dissolved hydrogen iluoride, may now be subjected to higher temperatures without danger of marked polymerization of the drying oil hydrocarbons. In order to separate the Inaphtha fraction from the desired drying oil product the washed hydrocarbon mixture of the two is transferred by means of pump |53 through line |5| containing valve |52 and line |54 containing valve |55 into heat exchanger |56 wherein the hydrocarbons are heated to a temperature within the range of from about 150 to about 200 C., which is somewhat above the boiling range of the present naphtha fraction. From heat exchanger |58 the hydrocarbon mixture is conveyed through line |51 containing valve |58 into naphtha fractionator |59 in which the lower boiling naphtha hydrocarbons are vaporized from the higher boiling drying oil hydrocarbons. The over-head vapors from fractionator |58, comprising essentially the naphtha fraction originally introduced into the system, pass through line |60 containing valve |6| into condenser |62 which has a rundown line |63 leading to receiver |64. The naphtha fraction accumulating in the latter receiver passes through line |65 containing valve |88 to pump |61 which recycles the naphtha fraction through line |68 and valve |88 into line 85, thus returning the naphtha either to the naphtha reservoir 18 (indicated as naphtha make-up) or through valve 81 into naphtha drier 88 for recycling into the process ow. Any water contained in the naphtha from the aqueous scrubbers heretofore mentioned is removed in naphtha vdryer 88 before recycling the sameinto thevprocess. Althoughl inthe above description it has been shown to be advantageous to caustic-wash the naphtha-drying oil mixture prior to distillation, it has sometimesbeen found more convenient (particularly when the separation of HF in column 83 .is virtually complete) to caustic-wash after the distillation in fractionator |58, in this casel it is neosary to wash only the drying oil recovered as bottoms.

The higher boiling drying oil hydrocarbons sep--v arated from the naphtha diluent in fractionating column |58 accumulate as a bottoms fraction in said column and are withdrawn therefrom through line |18 containing valve |1| and are charged by means of pump |12 into the drying4 oil fractionator hereinafter referred to. The drying oil product prepared in the present process is essentially a mixture containing hydrocarbons having various molecular weights. although the general structures and degrees of conjugated and non-conjugated unsaturation is similar in all fractions. Since the higher-boiling hydrocarbons contained in the drying oil product are more effective as drying oils than the lighter, more volatile components contained in the same mixture, it becomes desirable to make a separation of ,the more effective hydrocarbons from the components of lesser value. I have found in addition that a light oil fraction boiling from the initial boiling point up to about 300 or 325 C. at normal conditions is especially desirable for the preparation of resins therefrom by condensation of the fraction with other reactive organic compounds such as maleic anhydride, etc. but less desirable as a drying oil because of its volatility. A medium oil fraction containing hydrocarbon components of higher molecular weight than the components of the light oil fraction boils from about 300 to about 400 C. at normal conditions and this fraction has been found to possess valuable properties as a drying oil component in paints Yand varnishes and other coating compositions. If further separation of the product is desired, a heavy oil fraction containing hydrocarbon components having the highest molecular weight in the drying oil product may be separated as a residue or bottoms fraction from the drying oil fractionator and this fraction boils from about 400 C. up to the end boiling point. The latter fraction may also be used in coating compositions since it is partly resinous and further polymerizes and oxidizes on exposure to air to form a tough hard fllm. The present product is usually fractionated at a sub-atmospheric pressure (which may range from about l0 mm. up to atmospheric pressure) to eifect desirable separation and reduce the temperature to which the product must be heated in order to effect fractionation. The reduction in the boiling point temperature effected by lowering the column pressure eliminates or substantially reduces the tendency of the drying oil product to undergo thermal cracking into lower molecular weight hydrocarbons containing fewer unsaturate'd bonds. The vacuum may be maintained on the drying oil fractionating column by any suitable means such as the conventional vacuum pumps or aspirators inserted into any one of the vapor lines leading from the fractionator.

l 1a Il'oiurposesofthepresentdescriptimavaeuum fritionation procedure will be dcribed, although it is to be understood that fractionation at atmospheric pressure is also practicable and within the scope of the present invention. In the preferred operation of the present drying oil fractionation system, the pressure is maintained line |16 containing valve |11 and is introduced into drying oil fractionator |18 in the upper portion thereof where a light vapor fraction, boiling below about 300 C. at normal conditions, immediately flashes from the column into vapor line |18 containing valve |88 and is conveyed into condenser |8| where the vapor liqueiies into a light oil fraction. The latter ows through rundown pipe |82 containing valve |88 into receiver |84 from which it is withdrawn through line |85 containing valve |85 into storage or to a plant, not shown in the diagram where it is converted into by-products. Preferably, a portion thereof is withdrawn from line |85, through line |81 and valve |88, and is transferred by means of pump |88 into line |80 containing valvev |8|, and discharged into the top of fractionator |18 to provide said fractionator with a redux stream.

The medium oil fraction, hereinabove referred to and containing the preferred drying oil hydrocarbons, is withdrawn from fractionator |18 at a point intermediate between the uppermost and bottom plates 'in the fractionator corresponding to the desired boiling range at the medium oil fraction through line |82 containing valve |88, and is collected in receiver |84. Vapors with drawn with the liquid fraction and separating therefrom in receiver |84 are returned to the fractionator through line |84' to a higher plate in the column than the plate from which the fraction was removed. The medium oil fraction, boiling from about 300 to about 400 C. at normal conditions, is withdrawn from receiver |84, through line |85, cooling heat exchanger |86, line |81, and valve |98 into storage or to further points of utilization. The heavy oil fraction boiling from 400 C. up to the nnal boiling point at normal conditions is removed as a bottoms productfrom fractionator |18 through line |81, cooler 208, and line 200 and valve 280" into storage.

For the sake of simplicity in the description' of Figure 1, certain conventional units of apparatus, such as reboilers on the distillation columns and pressure control pumps have been omittedfrom the diagram. As an alternative in the fractionation of the naphtha-drying oil hydrocarbon mixture, it is also within the scope of the present in-l vention to fractionate the mixture at atmospheric pressure and to eliminate the separation of the heavy drying oil fraction boiling from' 400" C. and upwards, thereby making it possible to distill the naphtha fraction from drying oil hy-l drocarbons in a single column from which the naphtha fraction would be removed as the lowest boiling cut, the light oil fraction would be re moved as a cut boiling at a somewhat higher tem-1 perature, up to about 300 C. (at normal conditions) and a combined medium and heavy dry ing oil fraction would be removed from the frac-1 tionator as a bottoms material. It is, however,l

preferred, when it is desired to separate a product 'having maximum utility, to operate the process in the manner as heretofore described, that is by distilling the naphtha fraction from the drying oil product at atmospheric pressure and in a separate column, fractionating the dryingoil at a subatmospheric pressure. f

The unsaturated hydrocarbon fraction recovered from the hydrogen fluoride sludge and separated in the catalyst-packed column as a high boiling bottoms product according to the Vpresentv process contains a series of high molecular weight cyclic compounds of wide boiling range, but oi generally homologous structure which contain conjugated oleiinicy double bonds, although the exact composition of the fraction will-vary somewhat depending upon the particular charging stock, the catalyst utilized in the decomposition, and the conditions of operation employed. Infrared and ultra-violet adsorption studies as well as other analytical data determined on the unsaturated hydrocarbon material have shown that the polyenes contained therein are of cyclic structure but are substantially non-aromatic, and have isolated unsaturation in addition to the conjugated unsaturation, and that the four carbon atoms which constitute the conjugated system in said hydrocarbons are highlysubstituted, possessing, on the average, fewer Vthan two hydrogen atoms per mol as substituents.

Representative unsaturated polyolefnic hydrocarbon fractions which I have prepared and analyzed usually have` a wide boiling range of from about 150 to over 450 C., density of about 0.83 to about 0.93, index of refraction of about 1.47 to about 1.53 (but usually 1.48 to 1.50), speciiic dispersion of about 125 to about`-175 (but usually between 135 and 145), bromine numbers above about 140 (although they vary considerably with the average molecular weight), maleic anhydride values of about 30 to about 90 (usually in the range of about 45 to 85) acid number below 3, average number of olefinic double bonds per molecule varying between about 2.5 and about 4, of which from about 40 to about 70 per cent are conjugated, and average molecular weights from about 200 to about 400. although the usual average is in the neighborhood of 300. Unsaturated 4 i hydrocarbon fractions derived from hydrogen fluoride sludges have also been prepared in which some of the hydrocarbons have molecular weights of as low'as about 150 to as high as about1000. Although hydrogen to carbon atomic ratios of the hydrocarbons contained inthe unsaturated hy.. drocarbon fraction vary somewhat depending upon the particular source of the material, for a fraction derived from a polymer gasoline-hydrogen iiuoride sludge they range from about 1.67 to about 1.72 (for the various fractions) with the actual weight percentages of hydrogen varying from about 12.35 to about 12.6.

The properties of the unsaturated hydrocarbon products will, of course, vary somewhat depending upon whether the entire boiling rangel of material or a specic fraction is `obtained for analysis. In general, the lower boiling fractions have similar properties and are water-white to strawyellow in color, while the higher boiling fractions are generally somewhat darker land may vary more in properties, with differences in charge stock, conditions of preparation' etc.

The unsaturated polyoleilnic hydrocarbons containing conjugated and additional non-conjugated unsaturation recovered according to the present process have a special iield of utility in the manufacture of drying oils, paints. varnishes, lacquers, shellac substitutes and other protective coatings and for this purpose they may be mixed with varying proportions of natural glyceride drying oils or utilized independently in the composition of said products. Besides being a particularly desirable drying oil, the product of the present process may be utilized in the preparation of resins and plastics and a variety of synthetic organic compounds. For example, the hydrocarbons may be condensed with dienophilic acid anhydrides such as maleic, itaconic and mesaconlc acid anhydrides (or other derivatives) to form higher molecular weight acids or derivatives thereof. Such acids may be esteried or amidlzed to form resinous and plastic materials or other intermediates. The unsaturated properties of these hydrocarbons renders them suitable for halogenation to form halogen derivatives thereof from which insecticidal compositions may be prepared. Further, these hydrocarbons may be converted to derivatives of a variety of inorganic compounds for the preparation of detergents, siccatives, etc.

The following example is introduced for the purpose of illustrating the results obtainable by the process of the present invention, but it should not be construed so as to limit the scope of the invention disclosed herein or claimed in the following claims.

Ezample I The hydrogen fluoride sludge was prepared according to the following procedure: The hydrocarbon charging stock was a codimer gasoline having a boiling range indicated by the following Engler distillation:

Boiling Fraction Point Q Initial l 45 over 96 307 over 113 50 o over 120 70% overA 140 90% over 203 End Boiling point 256 an upper hydrocarbon phase containing only a small amount of dissolved hydrogen fluoride which was removed and washed with a dilute solution of sodium hydroxide; and a lower sludge layer containing substantially all of the hydrogen fluoride charged to the reactor. The upper hydrocarbon layer after being washed with dilute sodium hydroxide and deiiuorinated by passing the same over alumina at 200 C. yielded a gasoline of 300 F. E. P. having a clear octane rating of 87.1 and a leaded octane rating 2 cc. of tetraethyl lead added per gallon oi upper layer) of 99.1. The lower sludge layer formed in the sludge reactor was decanted therefrom and reserved for subsequent treatment as below. It containedv approximately 57% of hydrogen fluoride (believed to be practically all in a combined state as a hydrogen fluoride-hydrocarbon addition complex) and 43% hydrocarbons.

The sludge prepared as indicated above was extracted to remove dissolved and/or entralned saturated hydrocarbons by shaking the same with one volume of liquid pentane. The mixture was allowed to settle and separate into two layers. The lower sludge layer was decanted and mixed with two volumes of a straight-run naphtha fraction boiling within the range of from about 130 to about 140 C. The latter mixture was then heated to about 125 C. and flashed into an externally heated catalytic sludge decomposition polumn packed with particles of metallic copper as catalyst, said particles ranging in size from about 3 to about 10 mesh. An overhead hydrogen fluoride vapor condensed into liquid hydrogen fluoride containing 99.4% hydrogen fluoride and amounted to 98.4% of the hydrogen fluoride charged to the decomposition tower. The bottoms product from the decomposition tower was washed with an aqueous 10% caustic solution followed by washing the hydrocarbon fraction with water. The recovered hydrocarbon layer was heated to about 200 C. and flashed into a fractionating column. 'Ihe naphtha fraction flashing overhead as a vapor-was condensed and recycled to the process while the bottoms were removed. heated to about 225 C. and ashed into a vacuum fractionator maintained at a pressure of approximately 10 mm. mercury absolute. The distillate was separated into three fractions indicated in the following table:

Yield, Weight Percent oi Codi- Boil. Point, C. at Normal Conditions Diene No. l

Gardner Fraction Colo,

Light Oil Medium Oil Heavy Oil 300 400 and up.-.

` .Water at reaction conditions that result in the formation of a hydrogen fluoride sludge containing a hydrocarbon-hydrogen uoride addition complex, separating said sludge from the other reaction products, decomposing the hydrocarbonhydrogen fluoride complex by passing said sludge over a sludge decomposition catalyst at reaction conditions that result in the formation of a hydrogen fluoride vapor phase and a. liquid hydrocarbon phase, and separating said liquid hydrocarbon phase as said polyolefinic, polycyclic hydrocarbon mixture.

2. A process for the production of a hydrocarbon mixture containing polyoleilnic, polycyclic hydrocarbons, the unsaturated bonds of which are non-aromatic and in conjugated as well as non-conjugated relation to each other, which comprises contacting an oleflnic hydrocarbon containing at least 4 carbon atoms per molecule with a hydrogen uoride catalyst containing not more than about 10% water at reaction conditions that result in the formation of a hydrogen fluoride sludge containing a hydrocarbon- 23 n hydrogen uoride addition complex. separating said sludge from the other reaction products. mixing said sludge with-an inert hydrocarbon .diluent having an end boilingv point not in excess of about 150 C. in a volume ratio of said diluent to said sludge within'the range of from drogen iluoride vapor `phase and' a liquid hydrocarbon phase, removing said liquid hydrocarbon phase from the sludge decomposition zone and fractionating said liquid hydrocarbon phase into a fraction comprising said polyoleilnic, polycyclic hydrocarbon mixture and a fraction comprising said hydrocarbon diluent. l

3. 'I'he process of claim 2 further characterized in that said inert hydrocarbon diluent comprises a parailinic hydrocarbon having a normal boiling point within the range of from about 120 C. .to about 150 C.

4. The process of claim 2 further characterized in that said inert hydrocarbon diluent is 1 a straight-run naphtha fraction having a boiling point within the range of from about 120 Ito about 150 C. at normal conditions.

5. A process for the production of a hydroca bon mixture containing polyoleilnic, polycyclic hydrocarbons, the unsaturated bonds of which are non-aromatic and in conjugated as well as non-conjugated relation to each other, which comprises contacting an oleiinic hydrocarbon containing at least 4 carbon atoms per molecule with a hydrogen iluoride catalyst containing not l more than about water at reaction conditions that result in the formation of a hydrogen fluoride sludge containing a hydrocarbonhydrogen fluoride addition complex, separating said sludge from the other reaction products, extracting said sludge with a paraiilnic hydrocarbon which is in liquid phase and substantiallylinert under the conditions of extraction, to remove from said sludge the entrained and dissolved saturated hydrocarbons therein,` decomposing the hydrocarbon-hydrogen iluoride complex by passing said sludge in admixture with an inert liquid hydrocarbon diluent over a sludge decomposition catalyst at reaction conditions that result in the formation of a hydrogen fluoride vapor phase and a liquid hydrocarbon phase, and separating said liquid hydrocarbon phase containing said polyolefinic, polycyclic hydrocarbon mixture.

ing a hydrocarbon-hydrogen iluoride addition complexseparating said sludge from the other reactio products, mixing said sludge with an inert hydrocarbon diluent having an end boiling point not in excess of about 150 C. in a volume ratio of said diluent to said sludge within the range of from about 0.5 to about 10, passing the resultant mixture of sludge and diluent over la sludge decomposition catalyst at reaction conditions such that said diluent is retained in subacuosa stantially liquid phase ma ma sludge a decomposed into a hydrogen iiuoride vapor phase and a liquid hydrocarbon phase, removing said liquid v hydrocarbon phase from the sludge decomposition zone and fractionating the liquid hydrocarbon phase into a fraction comprising said inert hydrocarbon diluent as the lowest boilingy iraction thereof, a light oil fraction boiling up to about 300 C. at normal conditions and a .bottoms fraction comprising the residue o!4 said liquid hydrocarbon phase, and recoveringA said bottoms product. 4

8. A process for the product-ion of a hydrocarbon drying oil which comprises contacting an oleilnic hydrocarbon containing at least 4 carbon atoms per molecule with a hydrogeniluoride catalyst containing not more than about 10% water at reaction conditions .that result in the formation of a hydrogen iluoride sludge containing a hydrocarbon-hydrogen iluoride addition complex, separating said sludge from the other reaction products, mixing said sludge with an inert hydrocarbon diluent having an end boiling point not in excess of about150 C. in a volume ratio of said diluent to said sludge within the l range of from about 0.5 to about 10, passing the resultant mixture of sludge and diluent over a a liquid hydrocarbon phase, removing said liquid y hydrocarbon phase from thesludge decomposition zone and iractionating at atmospheric pressure said liquid hydrocarbon phase into an overhead fraction comprising said inert hydrocarbon diluent and a bottoms fraction comprising a high -boiling mixture of unsaturated hydrocarbons and fractionating said bottoms fraction at a subatmospheric pressure within the range of from' about 10 to about 100. mm. of mercury absolute to separate a light oil fraction boiling up to about 300 C. at normal conditions, a medium oil fraction boiling within the range of from about 300 to about 400 C. at normal conditions and a higher boiling bottoms fraction comprising the remainder of said liquid hydrocarbon phase, and recovering said bottoms product.

9. A process for the production ot a hydrocarbon drying oil which comprises contacting an olenic hydrocarbon containing at least 4 carbon atoms per molecule with a` hydrogen fluoride catalyst containing not more than about 10% water at reaction conditions that result' in the formation of a hydrogen iluoride sludge containing a hydrocarbon-hydrogen uoride Aaddition complex, separating said sludge'irom the other posed into a hydrogen fluoride vapor phase and a.

liquidihydrocarbon phase while at the same time passing a-carrier gas inert to the action of said hydrogen uoride sludge over the decomposition catalyst in countercurrent ow to said mixture of sludge and diluent, removing said liquid hydrocarbon phase and fractionating the same into a fraction comprising said inert hydrocarbon aclantis diluent and a fraction comprising said drying oil product. I

10. A process for the production of a hydrocarbon drying oil which comprises contacting an oleflnic codimer gasoline fraction having a boiling range of from about 30 C. to about 250 C. with a hydrogen fluoride catalyst containing not more than about water at reaction conditions that result in the formation of a hydrogen iluoride sludge containing a hydrocarbon-hydrogen fluoride addition complex, separating said sludge from the other reaction products, passing said sludge over a sludge decomposition catalyst at reaction conditions that result in the formation of a hydrogen fluoride vapor phase and a liquid hydrocarbon phase while at the same time passing a carrier gas inert to the action of said hydrogen iluoride over the decompositionv catalyst in countercurrent ow to said sludge, and removing the liquid` hydrocarbon phase as said drying oil product.

l1. The process of claim 9 further characterized in that said carrier gas is butane.

12. The process of -claim 9 further characterized in that said carrier gas is propane.

13. The process of claim 2 further characterized in that said inert hydrocarbon diluent is a saturated hydrocarbon fraction boiling within the range of from about 120 to about 150 C.

14. A process for the production of a hydrocarbon drying oil which comprises reacting an olenic hydrocarbon containing at least four carbon atoms per molecule in the presence of a 'carbon drying oil which comprises reacting a hydrogen fluoride catalyst, containing not more than about 10% water; separating the resultant reaction mixture into (1) an upper layer comprising saturated hydrocarbons formed during the reaction step and dissolved free hydrogen fluoride and (2) a lower layer comprising a hydrogen uoride-hydrocarbon complex and a relatively minor amount .of said saturated hydrocarbons; extracting said lower layer with a substantially inert liquid paramn solvent to remove saturated hydrocarbons therefrom; separating a solvent phase containing said saturated hydrocarbons and dissolved free hydrogen fluoride from the thus extracted complex; catalytically decomposing the latter to convert saidcomplex into a hydrogen fluoride vapor phase and a liquid hydrocarbon phase; commingling said solvent phase and said upper layer and distilling the resultant mixture to strip afraction comprising vapors oi' free hydrogen iluoride and said solvent from said saturated hydrocarbons; condensing the stripped vapors'to form a solvent layer and a hydrogen fluoride layer: returning said solvent layer to said exltraction step; returning said hydrogen uoride layer and hydrogen fluoride contained in said hydrogen iiuoride vapor phase to said reaction step: and fractionating said liquid hydrocarbon phase to recover therefrom a drying oil comprisins polyolenic polycyclic hydrocarbons containpolymer gasoline fraction in the presence of a hydrogen fluoride catalyst containing not more than about 10% water; separating the resultant reaction mixture into (1) an upper layer comprising saturated hydrocarbons formed during the reaction step and dissolved-free hydrogen fluoride and (2)v a lower layer comprising a hydrogen fluoride-hydrocarbon complex and a relatively minor amount of said saturated hydrocarbons; extracting said lower layer with liquid pentane to remove said saturated hydrocarbons therefrom; separating a pentane phase containing said saturated hydrocarbons and dissolved free hydrogen fluoride from the thus Aextracted complex; catalytically decomposing the latter to convert said complex into a hydrogen uoride vapor phase and a liquid hydrocarbon phase; commingling said pentane phase and said upper layer and distilling the resultant mixture to strip a fraction comprising vapors oi' free hydrogen fluoride and said pentane from said saturated hydrocarbons; condensing the stripped vapors to form a pentane layer and a hydrogen fluoride layer; returning said pentane layer to said extraction step; returning said hydrogen fluoride Alayer and hydrogen iluoride contained in said hydrogen fluoride vapor phase to said reaction step; and fractionating said liquid hydrocarbon phase to recover therefrom a drying oil comprising polyolenic polycyclic hydrocarbons containlng conjugated and non-conjugated unsaturation 18. The process of claim 17 further characterized in that said extracted complex is catalytically decomposed in the presence of a straight run naphtha traction boiling within the range of from about 120 C. to about 150 C. at reaction conditions such that said naphtha is retained in substantially liquid phase, and said naphtha is separated during said fractionation step and returned to said decomposition step.

ingconjugated and non-conjugated unsaturation.

15. The process o! claim 14 further charactex-ized in that said extracted complex is catalytically decomposed in the presence of a HERMAN St BLOCH.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS 

